My dad died last time I used a "single cause-effect", so don't use them.

If you use "slippery slope" someone will get angry at you and they will make you lose your job, which makes your girlfriend break up with you and lose your car and house, which makes you kill yourself.

Post Hoc: because one thing follows another, it is held to cause
the other Joint effect: one thing is held to cause another when in fact they
are both the joint effects of an underlying cause Insignificant: one thing is held to cause another, and it does, but it
is insignificant compared to other causes of the effect Wrong Direction: the direction between cause and effect is
reversed Complex Cause: the cause identified is only a part of the entire
cause of the effect

Begging the Question: the truth of the conclusion is assumed by
the premises Irrelevant Conclusion: an argument in defense of one conclusion
instead proves a different conclusion Straw Man: the author attacks an argument different from (and
weaker than) the opposition's best argument

Equivocation: the same term is used with two different meanings Amphiboly: the structure of a sentence allows two different
interpretations Accent: the emphasis on a word or phrase suggests a meaning
contrary to what the sentence actually says

Composition: because the attributes of the parts of a whole have
a certain property, it is argued that the whole has that property Division: because the whole has a certain property, it is argued
that the parts have that property

Affirming the Consequent: any argument of the form: If A then B,
B, therefore A Denying the Antecedent: any argument of the form: If A then B,
Not A, thus Not B Inconsistency: asserting that contrary or contradictory statements
are both true

Fallacy of Four Terms: a syllogism has four terms Undistributed Middle: two separate categories are said to be
connected because they share a common property Illicit Major: the predicate of the conclusion talks about all of
something, but the premises only mention some cases of the term
in the predicate Illicit Minor: the subject of the conclusion talks about all of
something, but the premises only mention some cases of the term
in the subject Fallacy of Exclusive Premises: a syllogism has two negative
premises Fallacy of Drawing an Affirmative Conclusion From a
Negative Premise: as the name implies Existential Fallacy: a particular conclusion is drawn from
universal premises

Subverted Support: (The phenomenon being explained doesn't
exist) Non-support: (Evidence for the phenomenon being explained is
biased) Untestability: (The theory which explains cannot be tested) Limited Scope: (The theory which explains can only explain one
thing) Limited Depth: (The theory which explains does not appeal to
underlying causes)

Fallacies of Definition

Too Broad: (The definition includes items which should not be
included) Too Narrow: (The definition does not include all the items which

Editor's Note: This information is from www.intrepidsoftware.com/fallacy/toc.php, with permission for reprint given at http://www.intrepidsoftware.com/fallacy/copyrite.php

(1) God is a being better than which cannot be conceived
(2) What's better, a God that exists or one that doesn't? One that does of course, so
(Conclusion)
God Must Exist.

Perhaps the same argument can be applied to prove the existence of the Perfect Pizza?

Aristotle on the other hand defines moral worth or goodness as fulfilling ones role as a rationalhuman. So why is it good to fulfil ones role as a rational human? Because fulfilling ones role as a rational human is good.

There are many other good fallacies. The Man in the Mask fallacy for example (another one old Des is guilty of). "I know what my father looks like, I do not know what the man in the mask looks like, therefore my father is not the man in the mask". The Appeal to Force is funny ("agree with me or I'll hit you") and apparently counts as a logical fallacy. Tell them that next time you get mugged.

A logical fallacy, as the term is usually understood, is an inadequate argument presented in support of a position, usually in the implied context of a debate. The argument is inadequate precisely because it does not support the position, for whatever reason. Why such a failure is called "logical" is not entirely clear: presumably because the discipline of logic had its roots in such debates, in trying to codify the cases when a particular conclusion was valid or invalid given certain premises.

The history of logical fallacies is a long one, stretching back to the Greco-Roman civilization. We might ask why they have received so much attention over the years, with lists being carefully drawn up, promulgated and pored over. Nowadays, the history, poetry, and drama of ancient times are quite unpopular, yet the ancient fallacies are still eagerly discussed. In Ancient Greece and particularly Rome, rhetoric, the art of making convincing speeches, was valued highly and studied intensively. As part of one's training, one would of course learn to identify and avoid (or employ in the most effective way?) all the classic fallacies. But clearly the study of fallacies feeds human needs much more durable than the outdated art of formal rhetoric.

These needs are easily identified as the Path of Least Resistance -- the human preference for a quick and decisive, though shallow, victory, over a deeper but knottier consideration of the issues -- and, above all, the joyous, self-affirming experience of finding and exposing someone else's mistake. (This really needs a long German word to describe it, like Schadenfreude.) It's much easier to identify a logical fallacy than to seriously engage with ideas. And, for every fallacy spotted, one gets the pleasure of patting one's own back for being so much more intelligent and objective than the other fellow.

With these psychologicalincentives, no wonder that sniping at logical fallacies remains a popular tactic. But like other blood sports, it runs the risk of becoming the unspeakable in pursuit of the undefensible.
A logical fallacy, ineffective though it may be, is at least an attempt to contribute to one side of a debate. Pointing out your opponent's logical fallacies in detail is one more step away from saying something relevant to the discussion. Although I have not experienced it first-hand, I am reliably informed that USEnet provides good examples of this descent from meaningful debate into quibbling. (Of course, if you like quibbling, that's different.)

So, what to do if your opponent does happen to use a logical fallacy? The only honourable course of action is to resist the temptation to exult or crow, but reply with a valid counter-argument which exposes by its own strength the weakness of the fallacy.

But this:
A -- (Same thing)
B -- Plato may be all of those things, but how can that alter the fact that goat's milk yoghurt is creamier, less acidic and contains a larger concentration of cancer-preventing antioxidants?1

Above all, do not commit the fallacy of imagining or claiming that you are right and your opponent is wrong because he or she has used a fallacy. Your ability to spot fallacies makes you a clever bastard, but does not make you right.

Being a clever bastard, and in the spirit of Godel's Theorem, I would like to call this argumentum ad fallaciem, the attempt to substitute fallacy-spotting for substantive argument. (This is clearly a subdivision of the fallacy of Style over Substance, in which one tries to argue that one's opponent is wrong because of the way in which he or she is arguing.) Any time an argument gets clogged up with "straw men", just mutter "argumentum ad fallaciem" and move on quickly.

1. I do not know whether either type of yoghurt contains cancer-preventing antioxidants. However, goat's milk yoghurt is delicious, and anyone who disagrees with that can go to Hades.